import java.util.ArrayList;
import java.util.Iterator;
import java.lang.String;

public class Strs implements Iterable<String>
{
    private ArrayList<String> st = new ArrayList<String>();

    public Strs(ArrayList<String> st)
    {
        st.add("aa");
        st.add("aaa");
        st.add("aba");
        st.add("cbb");
        st.add("c");
    }

    int count(ArrayList<String> st)
    {
        int c, fl;

        for(int i = 1; i < st.size(); i++)
        {
            c = 0;
            fl = 0;

            for (int j = i; j > 0; j--)
            {
                int val = st.get(i).compareTo(st.get(j));
                if (val == 0) c++;
            }

            if (c == i)
            {
                System.out.println(st.get(i));
                fl = 1;
            }

            return fl;
        }
    }

    //iterator_create
    public Iterator<String> iterator()
    {
        return new It();
    }
    //

    //iterator
    private class It implements Iterator<String>
    {

        private int pos;

        public It()
        {
            pos = 0;
        }

        public boolean hasNext()
        {
            int fl = count(st);

            if (fl == 1) return pos < st.size();
        }

        public String next()
        {
            return st.get(pos++);
        }
    }
    //

    //toString
    public String toString()
    {
        StringBuilder outStr = new StringBuilder("");
        outStr.append(this.first);
        outStr.append("   ");
        outStr.append(this.second);
        outStr.append(" => ");
        //outStr.append(this.sub); //common substring
        return String.valueOf(outStr);
    }
    //
}